ABSTRACT: Opioid analgesics are used routinely in managing acute musculoskeletal pain. However, physicians often hesitate to use them for chronic pain, such as that seen in rheumatoid arthritis, osteoarthritis, osteoporosis, and low back pain. Opioid analgesics are not firstline therapy for chronic pain; they should be used with other medications, such as nonopioid analgesics, anti-inflammatory drugs, muscle relaxants, antidepressants, anticonvulsants, topical preparations, and sleeping pills. A comprehensive patient assessment and an addiction history are essential. Consultation with a specialist in pain management often is helpful.

Key words: chronic musculoskeletal pain, opioid, analgesic

In many cases, the use of opioid analgesics for patients with chronic musculoskeletal pain is a legitimate treatment approach, and it is gaining acceptance in the medical community. Although some reports question the efficacy of long-term use of opioid analgesics in improving function,1 several randomized controlled trials of these agents showed at least a 30% reduction in pain.2 Although these medications are effective, physicians tend to underuse them because they lack knowledge about them and about addiction. They also fear regulatory scrutiny.

In part 2 of this 2-part article, I discuss how to assess patients who have chronic pain, determine the safety and appropriateness of treating them with opioid analgesics, and monitor them on a regular basis. In part 1 ("Chronic Musculoskeletal Pain: Rational Use of Opioid Analgesics, Part 1 "), I reviewed the properties and adverse effects of opioid analgesics and described the differences between physical dependency and addiction.

A COMPREHENSIVE TREATMENT PLAN

Opioid analgesics are not firstline therapy for chronic pain and are not recommended as the only treatment. They should be used as part of a comprehensive treatment plan that involves other medications and other modalities. Other medications to consider may include the following:

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Nonopioid analgesics, such as acetaminophen.

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Aspirin and other anti-inflammatory drugs.

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Muscle relaxants.

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Antidepressants (because patients with chronic pain often are depressed). (Low-dose tricyclic agents may have some utility in managing some chronic pain conditions, such as fibromyalgia syndrome [FMS] and neuropathic pain.) The dual selective serotonin-norepinephrine reuptake inhibitors (SSNRIs) duloxetine (Cymbalta) and milnacipran (Savella) also alleviate neuropathic pain; both are now FDA-approved for FMS.

Drugs that are used to counteract residual opioid sedation, including modafinil (Provigil) and methylphenidate (Ritalin).

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Sleeping pills (because patients who have chronic pain often have insomnia).

Optimal management of chronic pain involves a team effort. In addition to the primary care physician, possible team members include a rheumatologist, orthopedic surgeon, physiatrist, physical therapist, anesthesiologist, pain specialist (who can perform invasive procedures, such as epidural corticosteroid injections or nerve ablation, or insert a spinal cord stimulator or intrathecal pump), biofeedback specialist, hypnotist, acupuncturist, neurologist, neurosurgeon, addictionist, and psychologist. Psychotherapy, especially that involving cognitive-behavioral and spiritual therapies, may help some patients by teaching them how to be more accepting of their condition.

ASSESSING PATIENTS FOR OPIOID USE

Before a patient starts taking opioid analgesics for chronic pain, a comprehensive assessment is indicated. The first step is to assess the goal of treatment—is it to make a diagnosis of pain and eliminate it by removing the source or to allow the patient to live more comfortably with the pain?

Next, has the patient had a workup to determine the cause of the pain and the treatment options? For example, a patient with severe hip pain resulting from osteoarthritis might be best served by undergoing a hip replacement, which might result in no pain and improved function. Of course, this requires obtaining an adequate history of the pain problem, its onset and cause, and what treatments and medications have been used. If the pain problem is not new, obtaining old records from other treating physicians (including imaging studies, procedures, and consultations) is important.

A detailed description of the pain may help direct treatment. For example, neuropathic pain—pain related to direct nerve damage or injury—may benefit from treatment with anticonvulsants or the SSNRI antidepressants duloxetine and milnacipran that alleviate both depression and some types of neuropathic pain. Examples of this type of pain are peripheral neuropathy, postherpetic neuralgia, and reflex sympathetic dystrophy (now called chronic regional pain syndrome).

Note that musculoskeletal pain, such as low back pain, often has a neuropathic component (eg, sciatica). Therefore, a trial of an anticonvulsant or an SSNRI (eg, venlafaxine [Effexor] or duloxetine) may be worthwhile.

Taking an addiction history is essential to determine the appropriateness of considering opioid therapy. This history should include questions about the patient's present and past use of alcohol, cigarettes, or illegal drugs, as well as any family history of addiction problems. Administration of the Opioid Risk Tool3 or Screener and Opioid Assessment for Patients with Pain4 also is helpful. Old medical records should be examined for indications of previous problems with prescribed opioid analgesics. A physical examination in which particular attention is paid to the painful areas is needed to obtain additional information about the pain problem.

If the patient has not seen a physiatrist or an anesthesiologist who specializes in pain management, such a consultation may be extremely helpful. Both specialists can evaluate the role of local injections, physical therapy, transcutaneous electric nerve stimulation units, and other physical modalities in relieving pain. The physiatrist may recommend an assistive device, such as a wheelchair or braces. The anesthesiologist might consider placement of a spinal cord stimulator for some types of pain. If the patient has an addiction history or there are emotional or psychological issues, consultation with an addictionist or psychiatrist can be very informative.

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